Page 1 of 73 Diabetes Glucagon-like peptide-1 receptor agonists increase pancreatic mass by induction of protein synthesis Jacqueline A. Koehler1, Laurie L. Baggio1, Xiemin Cao1, Tahmid Abdulla1, Jonathan E. Campbell, Thomas Secher2, Jacob Jelsing2, Brett Larsen1, Daniel J. Drucker1 From the1 Department of Medicine, Tanenbaum-Lunenfeld Research Institute, Mt. Sinai Hospital and 2Gubra, Hørsholm, Denmark Running title: GLP-1 increases pancreatic protein synthesis Key Words: glucagon-like peptide 1, glucagon-like peptide-1 receptor, incretin, exocrine pancreas Word Count 4,000 Figures 4 Tables 1 Address correspondence to: Daniel J. Drucker M.D. Lunenfeld-Tanenbaum Research Institute Mt. Sinai Hospital 600 University Ave TCP5-1004 Toronto Ontario Canada M5G 1X5 416-361-2661 V 416-361-2669 F
[email protected] 1 Diabetes Publish Ahead of Print, published online October 2, 2014 Diabetes Page 2 of 73 Abstract Glucagon-like peptide-1 (GLP-1) controls glucose homeostasis by regulating secretion of insulin and glucagon through a single GLP-1 receptor (GLP-1R). GLP-1R agonists also increase pancreatic weight in some preclinical studies through poorly understood mechanisms. Here we demonstrate that the increase in pancreatic weight following activation of GLP-1R signaling in mice reflects an increase in acinar cell mass, without changes in ductal compartments or β-cell mass. GLP-1R agonists did not increase pancreatic DNA content or the number of Ki67+ cells in the exocrine compartment, however pancreatic protein content was increased in mice treated with exendin-4 or liraglutide. The increased pancreatic mass and protein content was independent of cholecystokinin receptors, associated with a rapid increase in S6 kinase phosphorylation, and mediated through the GLP-1 receptor.